code: def test_get_bg_mask_and_cmap():
      # non-regression test for issue #3120 (bg image was masked with mni
      # template mask)
      img, _ = _simulate_img()
      mask, cmap = html_stat_map._get_bg_mask_and_cmap(img, False)
      assert (mask == np.zeros(img.shape, dtype=bool)).all()
  
imports: import base64
  import warnings
  from io import BytesIO
  import numpy
  import pytest
  from matplotlib import pyplot
  from nibabel import Nifti1Image
  from nilearn import datasets, image
  from nilearn.image import get_data, new_img_like
  from nilearn.plotting import html_stat_map
  from ..js_plotting_utils import colorscale
label_desc: Use image node_id 10 for calling a global function with example usage: test_get_bg_mask_and_cmap() without return types